Tiêu chuẩn iso 16063 31 2009

Microsoft Word C036407e doc Reference number ISO 16063 31 2009(E) © ISO 2009 INTERNATIONAL STANDARD ISO 16063 31 First edition 2009 08 15 Methods for the calibration of vibration and shock transducers[.]

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Reference numberISO 16063-31:2009(E)

First edition2009-08-15

Methods for the calibration of vibration and shock transducers —

Part 31:

Testing of transverse vibration sensitivity

Méthodes pour l'étalonnage des transducteurs de vibrations et de chocs —

Partie 31: Essai de sensibilité aux vibrations transversales

Copyright International Organization for Standardization

Provided by IHS under license with ISO

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Foreword iv

1 Scope 1

2 Normative references 1

3 Uncertainty considerations 2

4 Determination of transverse sensitivity using a single-axis vibration generator 2

4.1 Apparatus 2

4.2 Method 2

4.2.1 Test procedure 2

4.2.2 Expression of results 3

5 Determination of the transverse sensitivity using a vibration generator with turntable 4

5.1 Apparatus 4

5.2 Method 6

5.3 Expression of results 6

6 Determination of transverse sensitivity using a test system with X- and Y-vibration generators 6

6.1 Apparatus 6

6.2 Method and expression of results 9

7 Determination of the transverse sensitivity using a tri-axial vibration generator 11

7.1 Apparatus 11

7.2 Method and expression of results 14

8 Equipment for measuring of the input and output signals of the transducer to be tested 15

9 Preferred amplitudes and frequencies 15

Annex A (normative) Definition of transverse sensitivity 16

Bibliography 18

Copyright International Organization for Standardization Provided by IHS under license with ISO

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`,,```,,,,````-`-`,,`,,`,`,,` -Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work of preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2

The main task of technical committees is to prepare International Standards Draft International Standards adopted by the technical committees are circulated to the member bodies for voting Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights ISO shall not be held responsible for identifying any or all such patent rights

ISO 16063-31 was prepared by Technical Committee ISO/TC 108, Mechanical vibration, shock and condition monitoring, Subcommittee SC 3, Use and calibration of vibration and shock measuring instruments

This first edition cancels and replaces ISO 5347-11:1993

ISO 16063 consists of the following parts, under the general title Methods for the calibration of vibration and shock transducers:

⎯ Part 1: Basic concepts

⎯ Part 11: Primary vibration calibration by laser interferometry

⎯ Part 12: Primary vibration calibration by the reciprocity method

⎯ Part 13: Primary shock calibration using laser interferometry

⎯ Part 15: Primary angular vibration calibration by laser interferometry

⎯ Part 21: Vibration calibration by comparison to a reference transducer

⎯ Part 22: Shock calibration by comparison to a reference transducer

⎯ Part 31: Testing of transverse vibration sensitivity

⎯ Part 41: Calibration of laser vibrometers

The following parts are planned:

⎯ Part 23: Angular vibration calibration by comparison to reference transducers

⎯ Part 32: Resonance testing1)

⎯ Part 42: Calibration of seismometers

1) Revision of ISO 5347-14:1993 and ISO 5347-22:1997

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Methods for the calibration of vibration and shock

The methods and techniques specified can be applied without re-mounting the transducer away from its mounting surface during the test, thus avoiding significant uncertainties often encountered in methods which require repeated mounting The different methods specified use a single-axis vibration exciter, a two-axis vibration exciter or a tri-axial vibration exciter Tri-axial vibration excitation allows the transverse sensitivity and the sensitivity on the geometric axis to be determined simultaneously, thus simulating application conditions where the transducer is exposed to multi-axial vibration

NOTE In accelerometer designs using a bending beam, the transverse sensitivity measured without any vibration acting on the geometric axis of sensitivity of the accelerometer may considerably differ from the transverse sensitivity measured in the presence of a vibration acting on the geometric axis of sensitivity (i.e when the bending beam is deflected by a vibration to be measured)

This part of ISO 16063 is applicable to a frequency range from 1 Hz to 5 kHz and for a dynamic range from

1 m/s2 to 1 000 m/s2 (frequency dependent) and from 1 mm/s to 1 m/s (frequency dependent) Although among all the systems specified it is possible to achieve these ranges, generally each has limitations permitting its use in much smaller ranges

The methods specified are by comparison both to a reference transducer and to a laser interferometer

The methods specified allow an expanded uncertainty of the transverse sensitivity (coverage factor k = 2) of

0,1 % or less to be achieved, if the expanded uncertainty is expressed as a percentage of the sensitivity of the test transducer in its sensitive axis

2 Normative references

The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies

ISO 266, Acoustics — Preferred frequencies

ISO 16063-1:1998, Methods for the calibration of vibration and shock transducers: Part 1: Basic concepts

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to make sure that the reported values of expanded uncertainty are credible

4 Determination of transverse sensitivity using a single-axis vibration generator

4.1 Apparatus

The single-axis test system of transverse sensitivity specified in this clause consists of a single-axis vibration exciter that is equipped with a specially designed fixture that enables the transducer under test to be mounted such that its geometric axis of sensitivity is perpendicular to the direction of motion of the vibration exciter table (where the direction of the motion of the vibration exciter table shown in Figure 1 is defined as the

Z-direction) It shall be possible to mount the test transducer at different angles about its sensitive axis,

preferably for continuous rotation over at least 180° An example (Reference [5]) of an octahedral fixture is shown in Figure 1

Another example is the use of an electro-dynamic long-stroke vibration exciter operated in combination with a turntable driven by a stepper motor as specified in Clause 5 The amplitude of the transverse acceleration of the fixture due to transverse motion inherent in the vibration exciter shall be less than 1 % of the acceleration

amplitude in the Z-direction at each of the test frequencies For cases in which the measured transverse

sensitivity is less than 2 % of the sensitivity measured on the geometric axis, the transverse motion of the vibration exciter shall meet even higher requirements (e.g 0,2 % at the test frequencies) To ensure that the transverse motion of the vibration exciter is sufficiently small, measurements of the transverse motion of the total setup (vibration exciter with fixture) with a load close in shape and weight to the transducer being tested should be performed beforehand or the transverse motion could be monitored during the measurement of the transverse sensitivity For the measurement of the input and output signal of the transducer to be tested, see Clause 8

The frequency rangeof the transverse test system is generally 1 Hz to 5 kHz, depending on the working range

of the vibration exciter, and on the mass of the fixtures and of the transducer tested Acceleration amplitudes from 1 m/s2 to 200 m/s2can be generated

4.2 Method

Vibrate the transducer at the reference amplitude and frequency on the geometric axis of sensitivity to

determine its sensitivity, SN (briefly referred to as S) Determine the values of transverse sensitivity as a function of frequency, ST, by vibrating perpendicularly to the sensitive axis of the transducer at different angles about its sensitive axis

The directions and magnitudes of the maximum and minimum transverse sensitivity shall be reported at a designated test frequency or as a function of frequency

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4 3

2 1

5 vibration exciter table

Figure 1 — Example of a fixture for mounting the test transducer with its sensitive axis perpendicular

to the direction of the vibration generated by the vibration exciter 4.2.2 Expression of results

Calculate the transverse sensitivity, S using Equation (1): T,

out T T

ˆˆ

u S a

ˆa is the amplitude of the acceleration in the test direction

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`,,```,,,,````-`-`,,`,,`,`,,` -Calculate the relative transverse sensitivity, S expressed as a percentage, using Equation (2): T*,

where S is the sensitivity of the transducer on the geometric axis of sensitivity

5 Determination of the transverse sensitivity using a vibration generator with

3 turntable controlled by a stepper motor

4 slide or air bearing

5 transducer to be tested

a(t) acceleration

ω1 angular frequency (“speed”)

Figure 2 — Example of a mechanical vibration exciter with turntable used for the measurement of the transverse sensitivity

The crank is driven at a constant speed, ω1, by an electric motor via a toothed belt The slider, in turn, drives a carriage, the motion of which is constrained by two bars with bronze sockets On the carriage, there is a turntable whose motion is controlled by a stepper motor The carriage is made to oscillate at approximately

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12 Hz with a 25,4 mm peak-to-peak amplitude, which corresponds to a root mean square (r.m.s.) acceleration value of 51 m/s2

The accelerometer to be tested is held in place on the turntable of the carriage through, for instance, a

¼-28 UNF hole drilled in the centre of the turntable Normally the accelerometer is placed such that the geometric axis is perpendicular to the direction of acceleration However, by using specially designed adaptors, the geometric axis of the accelerometer can be aligned with the direction of motion of the carriage Then, the sensitivity on the geometric axis of the accelerometer can be determined at the same excitation frequency as its transverse sensitivity The accelerometer then can be mounted with its geometric axis perpendicular to the direction of motion of the carriage to determine transverse sensitivity as a function of the orientation angle, as illustrated in Figure 3 The time to complete one revolution can be between 30 s and

120 s, depending on the resolution, especially for the direction of least cross-axis sensitivity

14

Key

1 power supply/coupler (or) charge amplifier 8 angular position controller for items 4 and 7

4 angular position detector part A 11 computer

6 transducer under test mounted on turntable 13 a.c motor

7 angular position detector part B 14 turntable control panel

Figure 3 — Example of block diagram of complete signal conditioning and data acquisition system

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`,,```,,,,````-`-`,,`,,`,`,,` -It is recommended that an accelerometer be permanently or periodically placed in the direction of the slider

motion to monitor the condition of the exciter By double integration, the value of amplitude of displacement

can be computed from the acceleration experienced in the excitation axis and hence a comparison drawn

between the observed value and the expected value (25,4 mm)

The transverse test system is generally operated at a fixed frequency between 5 Hz and 15 Hz and a fixed

displacement amplitude (25,4 mm peak-to-peak amplitude is widely preferred, see Note)

5.1.2 Vibration exciter assembly In the example introduced in 5.1.1, the vibration exciter consists

essentially of a three-phase synchronous a.c motor and a mechanical excitation unit The excitation unit itself

is composed of a crank-slider mechanism driving the carriage with the turntable, controlled by a stepper motor,

on to which the transducer under test is mounted With a power line frequency of 50 Hz, the synchronous

speed, n, is 1 500 r/min for the 4-pole motor in use

NOTE The use of a 3-phase, 4-pole synchronous motor is not mandatory To simplify the setup, a special

series-wound single-phase motor can be used working in a synchronous way with the power line frequency

5.1.3 Signal conditioning and data acquisition system In general, the output of the unit under test

requires signal conditioning, including filtering and amplification The signal conditioning unit may be

comprised of a power supply, voltage or charge amplifier, and a 24 dB/octave narrow analogue band-pass

filter which can be a combination of a high-pass and a low-pass filter The filtered signal is connected to the

input of the DVM which is in turn connected to a computer via a suitable digital interface Figure 3 shows a

block diagram of an example of a complete signal conditioning and data acquisition system

5.2 Method

Mount the transducer in a test arrangement such that the known vibratory motion in a plane perpendicular to

the sensitive axis is at least 100 times the motion in the direction of the sensitive axis The frequency and

amplitude of the motion shall be stated and shall lie within the rated frequency and amplitude ranges of the

transducer Determine the amplitude of maximum transverse sensitivity and the direction of the maximum and

minimum sensitivity by rotating the transducer about its geometric axis of sensitivity

NOTE Generally, the most interesting parameters are the maximum transverse sensitivity and the direction of the

minimum transverse sensitivity

5.3 Expression of results

Express the output at the maximum transverse sensitivity as a percentage of the output which would be

obtained if the known motion were applied in the direction of the geometric axis (Reference [7])

For further details, see 4.2.2 and Annex A

6 Determination of transverse sensitivity using a test system

with X- and Y-vibration generators

6.1 Apparatus

The transverse test system consists of at least two vibration exciters in the X–Y plane, X- and Y-axis reference

accelerometers, a power amplifier and a computer-based acquisition and control system In Figure 4 and

Figure 5, two versions of transverse vibration exciters are shown (see Reference [8] for Figure 4 and

Reference [9] for Figure 5) Both are designed to generate vibration in all possible directions in the X–Y plane,

yet keeping a fixed angular position of the transducer This is in contrast with the methods specified in

Clause 4, in which the motion is in a single direction and the transducer is turned through all angles to find the

direction of maximum transverse sensitivity

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1

4

5

6 3

1 X-axis reference accelerometer

2 Y-axis reference accelerometer

Figure 4 — Example 1 of a test system with X–Y plate

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`,,```,,,,````-`-`,,`,,`,`,,` -8 6

11 10

Key

1 X-axis reference accelerometer

2 Y-axis reference accelerometer

9 X-axis vibration exciter

10 Y-axis vibration exciter

11 frame

Figure 5 — Example 2 of a test system with X–Y plate

The first vibration exciter (see Figure 4) (Reference [8]) is a cylindrical rod cantilevered from a heavy base At the free end of the rod, the transducer to be tested is mounted with the sensitive axis parallel to the rod Piezoelectric bimorph actuators are attached to the rod, generally driven at the first natural flexural frequency

of the rod, to attain the large amplitudes and low-distortion waveforms at resonance

Tiêu đề	Methods for the calibration of vibration and shock transducers — Part 31: Testing of transverse vibration sensitivity
Trường học	International Organization for Standardization
Chuyên ngành	Calibration of Vibration and Shock Transducers
Thể loại	tiêu chuẩn
Năm xuất bản	2009
Thành phố	Geneva

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Số trang	24
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